O'Brien, Mark J. Esquire

511 West Bay Street Suite 330 Tampa, FL 33606


Updated: 10/05/2017


How long have you been an attorney?

Although it seems like just yesterday that I started my legal career, I am quickly approaching two decades as an attorney. They say that time flies when you love what you do and I certainly love what I do. Having been both a Miami prosecutor and a large firm defense practitioner, I made the decision nearly sixteen years ago to combine my different legal experiences to form a countrywide federal and statewide state criminal defense...


Office Info


  • English (Primary)
  • Spanish

Practice Areas

  • Criminal Defense
  • Federal Criminal Defense
  • Federal Criminal Appeals and Post-Conviction Motions
  • State Criminal Defense
  • State Criminal Appeals and Post-Conviction Motions
  • White Collar Criminal Defense
  • Mortgage Fraud Criminal Defense
  • Securities Fraud Criminal Defense


  • 100%

Representative Cases

  • Hulk Hogan v. Gawker Media, LLC (represented non-party witness Bubba the Love Sponge)
  • Florida Bar v. Adam Filthaut (prominent trial attorney accused of DUI setup in Bubba/MJ trial)
  • United States v. Jeanette Hevel (former Tampa Police Department Captain)
  • United States v. John Wilson (former Washington Redskin NFL player)
  • United States v. Rashia Wilson (IRS fraud)
  • United States v. Robert Blango (notorious Fort Myers bank robber)
  • United States v. Senad Djedovik (infamous Norwegian Cruse Lines employee)
  • State of Florida v. Rougned Odor (current Texas Ranger MLB player)
  • State of Florida v. Jerramy Stevens 1 (former Tampa Bay Buccaneer NFL player)
  • State of Florida v. Jerramy Stevens 2 (former Tampa Bay Buccaneer NFL player)
  • State of Florida v. Jerramy Stevens 3 (former Tampa Bay Buccaneer NFL player)
  • State of Florida v. Matthew Buendia (former United States Marine charged with shooting a police officer)
  • State of Florida v. Mary Lynn Vu (teacher accused of having sex with her student)


Bar Admissions

  • Florida, 1998
  • Massachusetts, 1998
  • U.S. District Court Middle District of Florida, 2002
  • U.S. District Court Northern District of Florida, 2008
  • U.S. District Court Southern District of Florida, 2013
  • U.S. District Court District of Massachusetts, 2003
  • U.S. Court of Appeals 1st Circuit, 2002
  • U.S. Court of Appeals 11th Circuit, 2003
  • Supreme Court of the United States of America, 2010
  • U.S. District Court Western District of Texas, 2015
  • U.S. District Court Eastern District of Arkansas, 2017
  • U.S. Court of Appeals 2nd Circuit, 2017

Other Affiliations

  • American Association for Justice (Member)
  • National Association of Criminal Defense Lawyers (Member)
  • Florida Association of Criminal Defense Lawyers (Member)
  • Florida Bar Association (Member)
  • Federal Bar Association (Member)

Classes and Seminars

  • Lecturer, Trial Advocacy Skills, Intensive Trial Advocacy Program (ITAP)

Past Positions

  • Office of the Miami-Dade County State Attorney


Offers Free Initial Consultation


Published Works

  • "Strategies For Defending Identity Theft Cases", Aspatore, 2012

Office Information


511 West Bay Street Suite 330 Tampa, FL 33606


  • 866-202-5964



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